The conversion of files and documents from one format to another format is required in a number of situations. These include, for example, for importing and exporting files on a PC or server between different applications requiring different formats, for converting documents for communication in particular protocols and for creating new files or documents from one or more existing files and documents. In creating such a new document or file from existing files and documents, it is typically the case that a considerable degree of manual intervention is necessary. In the specific case of a document authoring process, this conventionally involves manually composing documents, using a proprietary desktop authoring software application (MSWord, or Interleaf, for example). Such manual formatting and authoring is a time consuming and error prone operation and for documents that have predetermined document structures, the process becomes a burdensome, repetitive task.
There are transformation languages used in defining document formats, document presentation style or in converting document formats. One such Transformation language is DSSSL (Document Style Semantics and Specification Language) ISO 10179, 1996—Information Technology, which is a Scheme-like declarative language used to specify the formatting and transformation of SGML documents. Another such language is XSL (Extendible Style Sheet Language) specified in an ISO standard, (see http://www.w3.org/TR/xsl/), used to specify the style of XML documents as well as to format and to transform XML documents. A further proposed language is XSLT, XSL Transformations (see http://www.w3.org/TR/xslt/) based on XSL and which is specifically designed for XML transformation. However, these languages either lack flexibility, or are difficult to use or fail to provide the range of functions required to support adaptive file and document transformation. In addition, these languages are typically non-intuitive and lack the ability to specify complex structural document changes and fail to support high-level manipulations.
Applications also exist (such as Oracle Reports) that allow the output of data in a User selectable tabular style and in a User selectable format (e.g. PDF or HTML), for example, these applications are also constrained by many limitations. Such applications typically do not support automated file and document format conversion, require considerable manual intervention, and typically produce output data suitable for paper delivery only. These applications fail to provide the logical data structure information required to format documents to the extent required for their communication in composite form via electronic means such as via the Internet, for example. These deficiencies and associated problems are addressed by a system according to the invention principles.